This paper is by Marianne Camerer, co-founder and international director of Global Integrity, an international non-governmental organisation that tracks anti-corruption systems. Drawing on international best practice, she argues that the conditions that need to be in place to ensure that anti-corruption reforms are effective, sustainable and not easily subverted include: data to inform policy and strategy; comprehensive legal and institutional safeguards to prevent corruption and promote public interest; and, hardest to secure, political will and ethical leadership. She advocates for an array of interconnected institutions and oversight systems, as well as active engagement by civil society, the media, governments and business.